Arduino Due USART SPI is very, very slow?

The SPI USART is now working fine with a SCK of about 16.8 MHz, the write to dac functions are taking about 5-6 microseconds.
:slight_smile:

I also need to test the USART1, I could use it to read from an external ADC. Another option I have is to use the same USART SPI (USART0), once I'm defining the CS "manually".

Regards,
Danny

Due_USART0_SPI_Master_High_Freq.ino (6.72 KB)